Phylogenetic position of Scutellonema brachyurus (Nematoda: Hoplolaimidae) associated with tomato using 28S rDNA from South Africa

Plant parasitic nematodes are the main nematodes that live in the soil causing yield loss in various crops. Scutellonema species is ectoparasite and therefore can feed on the roots of tomatoes resulting in less production. This species must be identified correctly because it is a plant-parasitic and the tomato is one of the most important vegetable crops in Limpopo Province in South Africa. Therefore, this molecular study was conducted in 2022 at Limpopo University to identify the nematode from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Scutellonema brachyurus. Afterwards, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed South African S. brachuyurus had 99% similarity (MW504476; MW504474; JX472047; JX472045) with South Africa, and USA populations, respectively. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as S. brachyurus in the same clade with highly supported (100) bootstrap values. In conclusion, this species was identified using 28S rDNA however, the use of other rDNA markers such as ITS rDNA and mtDNA for a better understanding of Scutellonema phylogeny is recommended.